Pseudorotaxanes, rotaxanes and catenanes formed by metal ions templating

ABSTRACT

A pseudorotaxane, a rotaxane and a catenane are provided. The pseudorotaxane includes at least a macrocyclic host molecule, a guest molecule, and a metal ion. The host molecule contains at least a binding unit and an aromatic linking spacer. The guest molecule has at least a recognition unit. The metal ion is used to template the threading of the guest molecule through the macrocycle host molecule by coordinating to a binding pocket formed from the binding unit of the macrocycle and the recognition moiety of the guest molecule. Rotaxanes or catenanes can be synthesized from the pseudorotaxane complexes, with or without the metal template ion in their molecular structures.

BACKGROUND

1. Technical Field

The disclosure relates to a host-guest complex or an interlockedmolecule, especially a pseudorotaxane, a rotaxane or a catenane.

2. Description of Related Art

to Pseudorotaxanes, rotaxanes and catenanes are becoming increasinglyimportant materials for gelation, drug delivery, and molecularelectronics; therefore, efforts continue toward developing new threadingsystems and new methods to synthesize these intertwined and interlockedmolecules. Although many elegant interlocked molecular compounds andthreaded supramolecular complexes have been prepared in the past twodecades, the number of recognition motifs that can be exploited for thepreparation of these systems remains limited. This difficulty arisesmainly from the limited ability to incorporate suitable recognitionunits in an appropriate arrangement in the molecular structures of thehost and guest components, so that weak noncovalent interactions cancollaborate together to stabilize the resulting pseudorotaxanecomplexes. In addition, the lack of structural flexibility of therecognition units that can form pseudorotaxane complexes hinders theapplication of unique functions or structures into already practicallyused materials and/or biologically important (macro)molecules, many ofwhich do not contain the necessary, suitably arranged recognition unitsin their native molecular structures.

SUMMARY

Accordingly, in one aspect, the present invention is directed to apseudorotaxane complex, a rotaxane molecule, or a catenane molecule. Inthe complex or molecule, the recognition moiety of a guest molecule usedfor the host-guest assembly can contain only a simple functional group,such as a urea group, a carbamate group, an amide group, anoligo(ethylene glycol) group or a 2,6-bis(hydroxymethyl)pyridine group.

The pseudorotaxane complex comprises at least a host molecule, a guestmolecule, and a metal ion. The host molecule has a macrocyclic structurecomprising at least a binding unit and an aromatic linking spacers. Thebinding unit can be an oligo(ethylene glycol) group, or a2,6-bis(hydroxymethyl)pyridine group. The guest molecule has at least arecognition moiety, such as an urea group, a carbamate group, an amidegroup, an oligo(ethylene glycol) group, or a2,6-bis(hydroxymethyl)pyridine group. The metal ion coordinates to thebinding unit of the host molecule and the recognition moiety of theguest molecule.

According to an embodiment of this invention, the host molecule furthercomprises a binding assistant unit, such as an oligo(ethylene glycol)group, a 2,6-bis(hydroxymethyl)pyridine, a 2,2′-oxy-di(ethanethiol)group, a 1,3-bis(iminomethyl)benzene group or a2,6-bis(iminomethyl)pyridine group.

According to another embodiment, the aromatic linking spacer can be ap-xylenyl group or a 2,6-lutidinyl group.

According to yet another embodiment, the host molecule can be

According to yet another embodiment, the guest molecule contains atleast a glycine, a repeating unit of kevlar, or a repeating unit ofnylon-6,6.

According to yet another embodiment, the metal ion is Li⁺, Na⁺ or K⁺.

The rotaxane molecule or the catenane molecule comprises the hostmolecule(s) above and the guest molecule(s) above.

The rotaxane molecule or the catenane molecule also can comprise thereduced amine form(s) of the imine host molecule(s) above and the guestmolecule(s) above, i.e.

or

Accordingly, a new molecular recognition system has been discovered. Inthis new recognition system, a single recognition moiety of a threadedguest molecule can be recognized by a host molecule via a templatingmetal ion.

The foregoing presents a simplified summary of the disclosure in orderto provide a basic understanding to the reader. This summary is not anextensive overview of the disclosure and it does not identifykey/critical elements of the present invention or delineate the scope ofthe present invention. Its sole purpose is to present some conceptsdisclosed herein in a simplified form as a prelude to the more detaileddescription that is presented later. It is to be understood that boththe foregoing general description and the following detailed descriptionare by examples, and are intended to provide further explanation of theinvention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B are diagrams of the interaction between the host molecule,the guest molecule having a urea group, a carbamate group, an amidegroup, an oligo(ethylene glycol) group or a2,6-bis(hydroxymethyl)pyridine group and the metal ion.

FIG. 2 containing spectra 2A to 2F, and spectrum 2A is ¹H NMR spectrum(400 MHz, CDCl₃, 298 K) of the threadlike urea 1; spectrum 2B is ¹H NMRspectrum (400 MHz, CDCl₃, 298 K) of an equimolar mixture of urea 1 andMC1 (5 mM); spectra 2C-2F are ¹H NMR spectra (400 MHz, CDCl₃, 298 K) ofmixtures of urea 1, MC1, and NaTFPB at concentrations of 5/5/5 mM,5/10/10 mM, 5/15/15 mM, and 5/20/20 mM, respectively.

FIGS. 3A and 3B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100 MHz,CDCl₃, 298 K) spectra of rotaxane 1, respectively.

FIGS. 4A and 4B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100 MHz,CDCl₃, 298K) spectra of rotaxane 2, respectively.

FIGS. 5A and 5B are ¹H NMR (400 MHz, CD₃CN, 298 K) and ¹³C NMR (100 MHz,CD₃CN, 298 K) spectra of rotaxane 3, respectively.

FIGS. 6A and 6B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100 MHz,CDCl₃, 298 K) spectra of rotaxane 4, respectively.

FIGS. 7A and 7B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100 MHz,CDCl₃, 298 K) spectra of rotaxane 7, respectively.

FIGS. 8A and 8B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100 MHz,CDCl₃, 298 K) spectra of rotaxane 8, respectively.

FIGS. 9A and 9B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100 MHz,CDCl₃, 298 K) spectra of rotaxane 10, respectively.

FIGS. 10A and 10B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100MHz, CDCl₃, 298 K) spectra of rotaxane 12, respectively.

FIGS. 11A and 11B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100MHz, CDCl₃, 298 K) spectra of rotaxane 14, respectively.

FIGS. 12A and 12B are ¹H NMR (400 MHz, CD₃COCD₃, 298 K) and ¹³C NMR (100MHz, CD₃COCD₃, 298 K) spectra of rotaxane 17, respectively.

FIG. 13 is the solid state structure of rotaxane 16

FIGS. 14A and 14B are ¹H NMR (400 MHz, CD₃COCD₃, 298 K) and ¹³C NMR (100MHz, CD₃COCD₃, 298 K) spectra of rotaxane 18, respectively.

FIGS. 15A and 15B are ¹H NMR (400 MHz, CD₃COCD₃, 298 K) and ¹³C NMR (100MHz, CD₃COCD₃, 298 K) spectra of rotaxane 19, respectively.

FIGS. 16A and 16B are ¹H NMR (400 MHz, CD₃COCD₃, 298 K) and ¹³C NMR (100MHz, CD₃COCD₃, 298 K) spectra of rotaxane 20, respectively.

FIGS. 17A and 17B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100MHz, CDCl₃, 298 K) spectra of rotaxane 21, respectively.

FIGS. 18A and 18B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100MHz, CDCl₃, 298 K) spectra of rotaxane 23, respectively.

FIG. 19 containing spectra 19A-19C, and spectra 19A-19C are the partial¹H NMR spectra (400 MHz, CDCl₃, 298 K) displaying the formation ofcatenane 1 from an mixture of DAM1, DAD1, and NaTFPB (20 mM:20 mM:10 mM)for 0, 0.33, and 3 h, respectively.

FIGS. 20A and 20 B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100MHz, CD₃OD, 298 K) spectra of catenane 2, respectively.

FIGS. 21A and 21B are ¹H NMR (400 MHz, CD₃CN, 298 K) and ¹³C NMR (100MHz, CD₃CN, 298 K) spectra of catenane 4, respectively.

FIGS. 22A and 22 B are ¹H NMR (400 MHz, CD₃CN, 298 K) and ¹³C NMR (100MHz, CD₃CN, 298 K) spectra of catenane 6, respectively.

FIGS. 23A and 23B are ¹H NMR (400 MHz, CD₃CN, 298 K) and ¹³C NMR (100MHz, CD₃CN, 298 K) spectra of catenane 8, respectively.

FIGS. 24A and 24 B are ¹H NMR (400 MHz, CDCl₃, 298 K) and ¹³C NMR (100MHz, CDCl₃, 298 K) spectra of rotaxane 25, respectively.

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. It will be apparent,however, that one or more embodiments may be practiced without thesespecific details.

Pseudorotaxanes, Rotaxanes or Catenanes

In one aspect, a pseudorotaxane complex, a rotaxane or a catenane isprovided. The pseudorotaxane complex comprises at least a host molecule,a guest molecule, and a metal ion. The rotaxanes and catenanes bothcomprise a host molecule and a guest molecule, and the guest molecule ofthe catenanes having a macrocyclic structure.

The host molecule has a macrocyclic structure. The macrocyclic structurehas at least a binding unit and at least an aromatic linking spacer. Thebinding unit can be an oligo(ethylene glycol) group or a2,6-bis(hydroxymethyl)pyridine. The aromatic linking spacer can be ap-xylenyl group or a 2,6-lutidinyl group. Optionally, the macrocyclicstructure can further has a binding assistant unit, such as anoligo(ethylene glycol) group, a 2,6-bis(hydroxymethyl)pyridine, a2,2′-oxy-di(ethanethiol) group, a 1,3-bis(iminomethyl)benzene group, a1,3-bis(aminomethyl)benzene group, a 2,6-bis(iminomethyl)pyridine group,or a 2,6-bis(aminomethyl)pyridine group. For example, the macrocyclichost molecule can has one binding unit, one binding assistant unit, andtwo linking spacers respectively disposed between the binding unit andthe binding assistant unit to respectively link the binding unit and thebinding assistant unit. According to an embodiment, some examples of thehost molecule are listed in table 1 below.

TABLE 1 Some examples of the host molecule.

MC1

MC2

MC3

MC4

MC5

MC6

MC7

MC8

MC9

MC10

MC11

MC12

The guest molecule has at least a recognition moiety, such as a ureagroup, a carbamate group, an amide group, an oligo(ethylene glycol)group, or a 2,6-bis(hydroxymethyl)pyridine group.

The metal ion is used to template the threading of the guest moleculeabove through the macrocycle by coordinating to a binding pocket formedfrom the binding unit of the macrocyclic host molecule and therecognition moiety of the guest molecule. According to an embodiment,the metal ion can be an alkali metal ion, such as Li⁺, Na⁺ or K⁺. Forexample, the binding pocket can be formed from the oligo(ethyleneglycol) moiety of the macrocyclic host molecule, and the carbonyl (C═O)group or the ether (—CH₂—O—CH₂—) group of the guest molecule.

The interactions between the host molecule, the guest molecule, and themetal ion are shown in FIG. 1A and FIG. 1B. For better and easierillustrating the interactions between the host molecule, the guestmolecule, and the metal ion, the binding unit is presented by

the binding assistant unit is abbreviated as BAU, and the two linkingspacers are abbreviated as LS₁ and LS₂ in FIGS. 1A and 1B.

In FIG. 1A the guest molecule has a urea group, a carbamate group, or anamide group. In FIG. 1B, the guest molecule has an oligo(ethyleneglycol) group or a 2,6-bis(hydroxymethyl)pyridine group. In FIG. 1A or1B, the metal ion is used to template the threading of the guestmolecule through the macrocycle by coordinating to the binding pocketformed from the oligo(ethylene glycol) moiety or the2,6-bis(hydroxymethyl)pyridine moiety of the macrocycle, and the C═Ogroup (FIG. 1A), the ether group (FIG. 1B) or the2,6-bis(hydroxymethyl)pyridine (FIG. 1B) of the guest. In addition, [N—H. . . O] or [N—H . . . N] hydrogen bonds formed between the NH proton ofthe recognition moiety (i.e. the urea group, the carbamate group, or theamide group) to the oxygen or nitrogen atom in the binding assistantunit (BAU in FIGS. 1A and 1B), may help to further stabilize thestructure of the pseudorotaxane complexes.

Some examples of the pseudorotaxane complexes and the interlockedmolecules, such as rotaxanes and catenanes, are described below. Theformation of the pseudorotaxane complexes in solution is proven by thesuccessful synthesis of the corresponding rotaxanes or catenanes. Forsynthesizing a rotaxane molecule, a stoppering agent is used tointerlock the host molecule to prevent its dethreading from the guestcomponent. In the examples below, some stoppering agents were used, andare listed in table 2 below.

TABLE 2 Stoppering agent

SA1

SA2

SA3

SA4

SA5

SA6

SA7

A rotaxane or a catenane can also be synthesized through theself-assembly process, in which the recognition site of the guestmolecule was encircled by the macrocycle preformed or in situ generatedfrom the imine formation reaction of a dialdehyde and a diamine via thetemplating of metal ion. In the examples below, some dialdehydes anddiamines were used and are listed in table 3 below.

TABLE 3 Daldehydes and diamines used for the construction of catenanesDialdehydes Diamines

DAD1

DAM1

DAD2

DAM2

Embodiment 1 Guest Molecules Containing a Urea Group Example 1 Urea 1

In this example, urea 1 having a urea group conjugated to two aromaticrings was used as the guest molecule. MC1 was used as the host molecule.Since the hydrogen bonding between urea 1 and MC1 and the ion-dipoleinteraction between both of them and the metal ion template would bothprefer less-polar solvents, sodiumtetrakis(3,5-trifluoromethylphenyl)borate (NaTFPB) was chosen as thetemplating salt because of its relatively weak ion-pairing tendency insuch solvents. The chemical structure of NaTFPB is shown below.

Urea 1, MC1, and NaTFPB were mixed in various molar ratios in CDC₃ formeasuring ¹H NMR spectra. The obtained ¹H NMR spectra are shown inspectra 2C-2F in FIG. 2, respectively. In addition, the ¹H NMR spectraof urea 1 as well as an equimolar mixture of urea 1 and MC1 are alsoshown in spectra 2A and 2B in FIG. 2 for comparison.

First, spectra 2B and 2C in FIG. 2 are compared. Spectrum 2B is the ¹HNMR spectra of equimolar mixture of urea 1 and MC1 at a concentration of5 mM. In spectrum 2C, additional 5 mM NaTFPB was added to the CDClssolution. It can be clearly seen that the NMR signals of the urea 1(marked by H_(a), H_(b), and —CO—NH—, respectively) underwentsignificant shifts before and after adding NaTFPB. This observationsuggested that the efficient threading of urea 1 through MC1 requiredthe templating of Na⁺ ions, and the rates of complexation anddecomplexation were both fast on the ¹H NMR spectroscopic timescale at400 MHz and 298 K. The downfield shift of the signal of the NH protonsand the respective upfield and downfield shifts of those aromaticprotons H_(a) and H_(b) upon gradually increasing the concentrations ofMC1 and NaTFPB from 5 mM to 20 mM is consistent with the formation of apseudorotaxane between the host and guest components under theseconditions.

The downfield shift of the NMR signal of the NH protons can be explainedby the formation of [N—H . . . O] hydrogen bonds between the NH protonsof the urea moiety and the oxygen atoms of the diethylene glycolsegment. The respective upfield and downfield shifts of the signals ofthe protons H_(a) and H_(b) can be explained by the concomitantshielding and deshielding of the protons H_(a) and H_(b) by the p-xylenemotifs of the MC1.

Example 2 Urea 2

In this example, urea 2 having a urea group conjugated to two aromaticrings was used as the guest molecule. NaTFPB was used as the templatingsalt. SA1 was used as the stoppering agent. MC1, MC2 and MC3 wererespectively used as the host molecule. Di-n-butyltin dilaurate (DBTDL)was used as a catalyst for capping the SA1 to the urea 2. For preparingthe rotaxanes 1-3, a CH₂Cl₂ solution containing urea 2, NaTFPB, one ofthe host molecules, and DBTDL was added with SA1, and then stirred atambient temperature for 16 hours.

The macrocycle interlocked in rotaxane 2 is MC2, in which the twodiethylene glycol motifs in MC1 were replaced by a triethylene glycoland a 2,6-bis(hydroxymethyl)pyridine units. The higher yield in thesynthesis of rotaxane 2 compared to the one of rotaxane 1, suggestedthat the 2,6-bis(hydroxymethyl)pyridine unit is a more preorganized andbetter chelating motif, which energetically overcomes the increasingstructural flexibility introduced by the triethylene glycol unit in thehost-guest complexation.

MC3, in which two oxygen atoms in the diethylene glycol moiety of MC1were replaced by sulfur atoms, gave significantly lower yield in thesynthesis of its interlocked rotaxane 3. This result may due to therelative flexible molecular structure and the weaker interaction of itsbinding assistant unit (BAU) to the NH proton of the guest molecule ofMC3. Nevertheless, with the assistance from the Na⁺ ion template, MC3and urea 2 still can form pseudorotaxane complexes in solution and thecorresponding rotaxane 3 was isolated in 9% yield.

The observation of no signal corresponding to TFPB anion in the ¹H NMRspectra of the [2]rotaxane 1-3, suggested the templating Na ion wascompletely removed during the aqueous extraction and chromatographyprocess. This result also suggested that the complexation of the Na⁺ ionto the binding pocket in the [2]rotaxanes was not particularly strongunder these conditions. The bulky terminal groups of the threaded guest,however, prevent the dethreading of the interlocked macrocycle evenafter the loss of the metal ion template.

The ¹H NMR and ¹³C NMR spectra of rotaxanes 1, 2 and 3 are shown inFIGS. 3, 4 and 5, respectively. All related spectral data are listedbelow.

rotaxane 1: M.p. 126-127° C.; ¹H NMR (400 MHz, CDCl₃): δ=1.30 (s, 18H),1.36 (s, 18H), 3.49-3.70 (m, 16H), 4.27 (d, J=11.2 Hz, 1H), 4.28 (d,J=11.2 Hz, 1H), 5.06 (s, 2H), 6.72 (d, J=8 Hz, 2H), 6.78 (s, 1H),6.83-6.91 (m, 12H), 7.03 (s, 1H), 7.09-7.14 (m, 4H), 7.26 (s, 1H); ¹³CNMR (100 MHz, CDCl₃): δ=31.4, 31.6, 34.9, 34.9, 66.6, 68.7, 70.6, 73.2,113.0, 114.4, 115.9, 117.1, 119.0, 128.1, 128.1, 128.8, 136.3, 137.3,138.7, 138.9, 150.2, 151.2, 153.2 (one signal is missing, possiblybecause of signal overlap). HRMS (ESI): m/z [M+H]⁺: C₆₁H₈₃N₃O₉, calcd.1002.6208. found 1002.6233; [M+Na]⁺: C₆₁H₈₃N₃O₉Na calcd. 1024.6027.found 1024.6011.

rotaxane 2: ¹H NMR (400 MHz, CDCl₃, 298 K): δ=1.31 (s, 18H), 1.33 (s,18H), 3.33-3.50 (m, 4H), 3.61-3.70 (m, 8H), 4.38 (s, 4H), 4.52 (d, J=5.6Hz, 4H), 4.56 (d, J=1.6 Hz, 4H), 4.91 (s, 2H), 6.73 (d, J=8.4 Hz, 2H),6.86 (d, J=8.4 Hz, 2H), 7.00-7.10 (m, 9H), 7.12 (d, J=1.6 Hz, 1H), 7.18(d, J=1.6 Hz, 2H), 7.30 (s, 2H), 7.40 (d, J=7.6 Hz, 2H), 7.46 (s, 1H),7.57 (s, 1H), 7.63 (b, 1H), 7.76 (t, J=7.6 Hz, 1H); ¹³C NMR (100 MHz,CDCl₃, 298 K): δ=31.4, 31.5, 34.8, 34.8, 66.5, 69.0, 70.6, 70.9, 71.8,73.0, 112.9, 113.2, 116.0, 117.1, 118.1, 120.6, 127.7, 128.2, 128.3,128.4, 136.0, 137.4, 137.7, 137.7, 139.1, 139.2, 151.0, 151.5, 151.7,153.7, 157.6 (one signal is missing, possibly because of signaloverlapping); HR-MS (ESI): calcd for C₆₁H₈₇N₄O₉ ⁺ [M+H]⁺, m/z 1079.6468.found, m/z 1079.7648.

rotaxane 3: ¹H NMR (400 MHz, CD₃CN): δ=1.29 (s, 18H), 1.35 (s, 18H),2.43-2.58 (m, 4H), 3.43-3.57 (m, 8H), 3.68-3.79 (m, 8H), 4.30 (s, 4H),4.90 (s, 4H), 6.88 (d, J=8.2 Hz, 2H), 6.94 (d, J=8.0 Hz, 2H), 7.03 (d,J=8.5 Hz, 2H), 7.07-7.14 (m, 4H), 7.19-7.24 (m, 3H), 7.28-7.35 (m, 3H),7.70 (br s, 1H); ¹³C NMR (100 MHz, CD₃CN): δ=30.1, 31.7, 31.8, 35.6,35.6, 35.9, 69.9, 70.4, 71.6, 73.8, 113.8, 114.0, 116.5, 118.8, 128.7,129.2, 129.3, 130.2, 136.6, 138.6, 138.6, 139.2, 140.5, 140.6, 151.7,151.9, 152.0, 154.3 ppm (one signal is missing, possibly because ofoverlapping); HRMS(ESI): calcd for C₆₁H₈₃N₃O₇S₂Na⁺ [M+Na]⁺, m/z1056.5570. found, m/z 1056.5595.

In addition, another comparative experiment was done under a conditionsimilar to the one used in the synthesis of rotaxane 1, but without theaddition of NaTFPB. The ¹H NMR spectrum of the crude product displayedno detectable signals corresponding to rotaxane 1, which indicated thatthe Na⁺ ion template is crucial for efficiently threading the urea unitthrough the cavity of MC1.

Example 3 Urea 3

In this example, urea 3 having a urea group conjugated to two aromaticrings was used as the guest molecule and SA2 was used as the stopperingagent, because the 3,5-di-t-butylphenyl group in urea 2 and SA1 is notsterically bulky enough to prevent the dethreading of MC4. NaTFPB wasused as the templating salt. DBTDL was used as a catalyst for cappingthe SA2 to the urea 3. For preparing the rotaxanes 4, a CH₂Cl₂ solutioncontaining urea 3, NaTFPB, MC4, and DBTDL was added with SA2, andstirred at ambient temperature for 16 hours.

The macrocycle interlocked in rotaxane 4 is MC4, which different to MC1is by replacing one of its diethylene glycol chains with a triethyleneglycol one. The large terminal groups are required to prevent thedethreading of MC4. The lower yield in the synthesis of rotaxane 4simply reflected that MC4 is a more flexible and less preorganized hostfor such a Na⁺ ion templating host-guest complexation system, even itcontains one more oxygen atom for the N—H groups in urea 3 to interactwith. Nevertheless, with the assistance from the Na⁺ ion template, MC4and urea 3 still can form pseudorotaxane complexes in solution androtaxane 4 was isolated in 13% yield.

The ¹H NMR and ¹³C NMR spectra of rotaxane 4 are shown in FIGS. 6A and6B, respectively. All related spectral data are listed below.

rotaxane 4: ¹H NMR (400 MHz, CD₃COCD₃): δ=1.30 (s, 27H), 1.32 (s, 27H),3.40-3.45 (m, 4H), 3.54-3.59 (m, 8H), 3.61 (s, 4H), 3.66-3.70 (m, 4H),4.29-4.40 (m, 8H), 5.01 (s, 2H), 6.94-7.04 (m, 10H), 7.08 (d, J=8.8 Hz,2H), 7.11-7.20 (m, 14H), 7.24 (d, J=8.4 Hz, 2H), 7.30-7.37 (m, 14H),7.39 (d, J=8.8 Hz, 2H), 7.54 (s, 1H), 7.70 (s, 1H), 8.53 (s, 1H); ¹³CNMR (100 MHz, CDCl₃): δ=31.4, 31.4, 34.3, 34.3, 63.2, 66.8, 68.8, 69.3,70.6, 70.7, 70.9, 73.2, 117.1, 118.1, 124.0, 124.0, 127.7, 127.8, 127.9,128.6, 128.8, 130.7, 130.8, 131.3, 131.8, 135.8, 136.7, 136.8, 137.2,139.6, 140.5, 142.2, 143.9, 144.2, 148.2, 148.3, 151.4, 153.6; HRMS(ESI): m/z [M+Na]⁺: C₁₀₉H₁₃₁N₃O₁₀Na cal. for 1664.9732. found 1664.9727.

Example 4 Urea 4

In this example, urea 4 having a urea group conjugated to one aromaticring was used as the guest molecule. NaTFPB was used as the templatingsalt. MC1 was used as the host molecule. SA1 was used as the stopperingagent. For preparing the rotaxane 5, a CH₂Cl₂ solution containing urea4, NaTFPB and MC1 was added SA1 and stirred at ambient temperature for16 hours.

All related spectral data of rotaxane 5 are listed below.

rotaxane 5: M.p. 120-121° C.; ¹H NMR (400 MHz, CDCl₃): 8=1.34 (s, 36H),3.50 (s, 16H), 3.60-3.70 (br, 4H), 4.30 (s, 8H), 4.74-4.82 (br, 2H),6.66-6.71 (br, 2H), 6.84 (s, 4H), 7.06 (s, 8H), 7.10 (s, 2H), 7.27 (s,4H); ¹³C NMR (100 MHz, CDCl₃): δ=31.6, 35.0, 43.3, 68.7, 70.6, 73.4,114.0, 116.4, 127.1, 129.0, 136.7, 137.4, 139.0, 151.2, 155.3; HRMS(ESI): m/z [M+H]⁺: C₆₂H₈₇N₄O₈, calcd. 1015.6511. found 1015.6523;[M+Na]⁺: C₆₂H₈₆N₄O₈Na calcd. 1037.6343. found 1037.6317.

Example 5 Urea 5

In this example, urea 5 having a urea group conjugated to no aromaticrings was used as the guest molecule. NaTFPB was used as the templatingsalt. MC1 or MC5 was used as the host molecule. SA1 was used as thestoppering agent. DBTDL was used as a catalyst for capping the SA1 tothe urea 5. For preparing the rotaxanes 6 and 7, a CH₂Cl₂ solutioncontaining urea 5, NaTFPB, one of the host molecules, and DBTDL wasadded with SA1 and stirred at ambient temperature for 16 hours.

All related spectral data of rotaxane 6 and 7 are listed below. The ¹Hand ¹³C NMR spectra of rotaxane 7 were shown in FIGS. 7A and 7B,respectively.

Rotaxane 6: M.p. 113-114° C.; ¹H NMR (400 MHz, CDCl₃): δ=0.77 (t, J=5.6Hz, 2H), 1.32 (s, 18H), 1.34 (s, 18H), 1.92-2.00 (br, 2H), 3.19 (t,J=5.2 Hz, 2H), 3.40-3.59 (m, 16H), 4.29 (s, 8H), 4.33 (d, J=5.2 Hz, 2H),4.40-4.46 (s, 1H), 5.29-5.34 (s, 1H), 7.07 (d, J=1.6 Hz, 1H), 7.14 (s,8H), 7.20 (s, 2H), 7.31 (J=1.2 Hz, 1H), 7.37 (s, 2H), 7.80-7.84 (br,1H); ¹³C NMR (100 MHz, CDCl₃): δ=27.8, 31.5, 31.5, 34.8, 34.9, 37.4,45.2, 63.6, 68.9, 70.5, 73.5, 112.7, 116.2, 121.2, 122.8, 129.1, 137.0,138.7, 139.1, 150.9, 151.3, 153.3, 158.0; HRMS (ESI): m/z [M+H]⁺:C₅₈H₈₆N₃O₉ calcd. 968.6364. found 968.6343; [M+Na]⁺: C₅₈H₈₆N₃O₉Na calcd.990.6184. found 990.6158.

Rotaxane 7: ¹H NMR (400 MHz, CD₃COCD₃, 298 K): δ=0.80 (t, J=6.4 Hz, 2H),1.30 (s, 18H), 1.31 (s, 18H), 2.27-2.35 (m, 2H), 3.27 (t, J=6.4 Hz, 2H),3.55-3.66 (m, 8H), 4.12 (d, J=5.4 Hz, 2H), 4.35 (s, 4H), 4.52 (s, 4H),4.55 (s, 4H), 4.82 (s, 1H), 5.47 (t, J=5.2 Hz, 1H), 7.11 (t, J=1.7 Hz,1H), 7.16-7.19 (m, 10H), 7.35-7.40 (m, 5H), 7.77 (t, J=7.8 Hz, 1H), 8.49(s, 1H); ¹³C NMR (100 MHz, CD₃COCD₃, 298 K): δ=31.8, 31.9, 35.3, 35.4,37.4, 45.2, 63.6, 69.9, 71.2, 72.1, 73.3, 73.7 (one signal is missingpossibly because of signal overlapping), 113.4, 116.7, 121.2, 121.5,123.2, 129.4, 129.5, 137.9, 138.3, 138.5, 140.2, 140.9, 151.3, 151.8,154.0, 158.4, 158.5; HR-MS (ESI): calcd for C₆₁H₈₄N₄NaO₈ ⁺ [M+Na]⁺, m/z1023.6181. found, m/z 1023.6158.

The urea groups in urea 2, 4 and 5, were conjugated to two, one and zeroaromatic rings, respectively. The yields of the corresponding rotaxanes1, 5, and 6 were 40%, 25%, and 8%, respectively. This result may beexplained by the acidity enhancement of the urea NH groups whenconjugated to more aromatic rings, which increases the stability andconcentration of the pseudorotaxanes in solution and thus, increases thesynthetic efficiency of the corresponding rotaxanes.

Embodiment 2 Guest Molecule Containing a Carbamate Group Example 6Carbamate 1

In this example, carbamate 1 having a carbamate group conjugated to onearomatic ring by its NH motif was used as the guest molecule. NaTFPB wasused as the templating salt. MC1 was used as the host molecule. SA1 wasused as the stoppering agent. DBTDL was used as a catalyst for cappingthe SA1 to the carbamate 1. For preparing the rotaxane 8, a CH₂Cl₂solution containing carbamate 1, NaTFPB, DBTDL and MC1 was added SA1 andstirred at ambient temperature for 16 hours.

Possibly because the conjugation to aromatic ring increases the acidityof the NH moiety of the carbamate group, pseudorotaxanes formed fromcarbamate 1, MC1 and NaTFPB were relatively stable in solution, and theyield of rotaxane 8 was up to 34%.

The ¹H NMR and ¹³C NMR spectra of rotaxane 8 are shown in FIGS. 8A and8B, respectively. All related spectral data are listed below.

rotaxane 8: ¹H NMR (400 MHz, CDCl₃): δ=0.69-0.75 (m, 2H), 1.15-1.21 (m,4H), 1.37 (s, 36H), 3.18 (t, J=6 Hz, 2H), 3.56-3.70 (m, 16H), 4.32 (d,J=10.4 Hz, 4H), 4.36 (d, J=10.4 Hz, 4H), 7.10 (t, J=1.6 Hz, 1H), 7.13(t, J=1.6 Hz, 1H), 7.17 (s, 8H), 7.42 (d, J=1.6 Hz, 2H), 7.54 (d, J=1.6Hz, 2H), 7.85 (s, 1H), 7.98 (s, 1H); ¹³C NMR (100 MHz, CDCl₃): 6=23.3,31.5, 31.5, 33.3, 34.9, 34.9, 63.5, 68.9, 70.5, 73.4, 112.1, 113.5,116.0, 116.6, 129.0, 136.9, 138.5, 138.7, 150.8, 151.0, 153.3, 171.3(one signal is missing possibly because of signal overlapping); HRMS(ESI): m/z [M+H]⁺: C₅₈H₈₅N₂O₁₀ calcd. 969.6204. found 969.6185; [M+Na]⁺:C₅₈H₈₄N₂O₁₀Na calcd. 991.6024. found 991.6011.

Example 7 Carbamate 2

In this example, carbamate 2 having a carbamate group conjugated to noaromatic ring was used as the guest molecule. NaTFPB was used as thetemplating salt. MC1 was used as the host molecule. SA3 was used as thestoppering agent. For preparing the rotaxane 9, a sticky liquid obtainedfrom concentrating a CH₂Cl₂ solution containing MC1, NaTFPB andcarbamate 2 was added SA3 (in neat), and stirred at ambient temperatureuntil solidified.

Since the carbamate group in carbamate 2 is not conjugated to anyaromatic rings, its NH moiety in less acidic and the synthesis ofrotaxane 9 is less efficient in solution. This problem was resolved byconcentrating a CH₂Cl₂ solution mixture of MC1, NaTFPB and carbamate 2to afford a neat mixture containing the corresponding pseudorotaxane andreacting it with SA3 under solvent-free condition. Rotaxane 9 can beisolated in 10% yield by using this approach.

All related spectral data of rotaxane 9 are listed below.

rotaxane 9: ¹H NMR (400 MHz, CDCl₃): δ=0.98-1.08 (m, 2H), 1.33 (s, 36H),3.35 (t, J=6.8 Hz, 4H), 3.39-3.51 (m, 16H), 4.13 (d, J=2.4 Hz, 4H), 4.30(s, 8H), 5.60 (t, J=5.6 Hz, 2H), 7.11 (s, 12H), 7.31 (s, 2H); ¹³C NMR(100 MHz, CDCl₃): δ=31.6, 34.9, 45.8, 61.6, 68.5, 70.2, 73.1, 121.2,122.6, 128.6, 137.0, 137.6, 150.7, 156.1 (one signal is missing,possibly because of signal overlap); HRMS (ESI): m/z [M+H]⁺ C₅₉H₈₇N₂O₁₀calcd. 983.6361. found 983.6397; [M+Na]⁺: C₅₉H₈₆N₂O₁₀Na calcd.1005.6180. found 1005.6199.

Embodiment 3 Guest Molecules Containing at Least One Amide Group Example8 Amide 1

In this example, guest amide 1 has an amide group conjugated to twoaromatic rings and represents a repeating unit of a para-aramidsynthetic fiber, Kevlar. NaTFPB was used as the templating salt. MC1 wasused as the host molecule. SA4 was used as the stoppering agent.Diisopropylethylamine (DIPEA) was used as a base to remove the HClgenerated during the reaction. For preparing the rotaxane 10, a CH₂Cl₂solution mixture of amide 1, NaTFPB, MC1 and DIPEA was added with SA4and stirred at ambient temperature for 16 hours.

Due to the Kevlar polymer was synthesized by reacting monomers1,4-phenylene-diamine and terephthaloyl chloride in solution, SA4 waschosen as the stoppering agent to react with the aniline of amide 1 tomimic the polymerization process of the Kevlar polymer. The isolation ofrotaxane 10 is suggested that such a Na⁺ ion templating host-guestrecognition system can be used to generate pseudorotaxanes or rotaxanesfrom the polymer without alternating much of its synthetic process. Thelow yield (3%) of rotaxane 10 can be rationalized by the release of thechloride anions during the reaction progress, which destabilized thepseudorotaxane intermediate by weakening the metal ion chelating and/orhydrogen bonding interactions among the components.

The ¹H NMR and ¹³C NMR spectra of rotaxane 10 are shown in FIGS. 9A and9B, respectively. All related spectral data are listed below.

rotaxane 10: ¹H NMR (400 MHz, CDCl₃): δ=1.42 (s, 36H), 3.50-3.60 (m,8H), 3.61-3.69 (m, 8H), 4.22 (s, 8H), 6.84 (s, 8H), 7.13 (s, 4H), 7.56(t, J=1.6 Hz, 2H), 7.73 (d, J=1.6 Hz, 4H), 8.36 (s, 2H); ¹³C NMR (100MHz, CDCl₃): δ=31.5, 35.1, 69.0, 70.6, 73.4, 120.4, 121.7, 124.9, 127.9,133.7, 136.1, 136.2, 150.7, 165.9; HRMS (ESI): m/z [M]⁺: C₆₀H₈₀N₂O₈calcd. 956.5914. found 956.5902.

Example 9 Amide 2

In this example, amide 2 having its NH moiety conjugated to an aromaticring was used as the guest molecule. NaTFPB was used as the templatingsalt. MC1 was used as the host molecule. SA1 was used as the stopperingagent. DBTDL was used as a catalyst for capping the SA1 to the amide 2.For preparing the rotaxane 11, a CH₂Cl₂ solution containing amide 2,NaTFPB, MC1 and DBTDL was added SA1 and stirred at ambient temperaturefor 16 hours.

Characterization data for rotaxane 11: M.p. 176-177° C.; ¹H NMR (400MHz, CDCl₃): δ=0.70-0.76 (m, 2H), 1.17-1.21 (m, 2H), 1.37 (s, 36H), 3.18(t, J=6 Hz, 2H), 3.58-3.70 (m, 16H), 4.33 (d, J=10.4 Hz, 4H), 4.36 (d,J=10.4 Hz, 4H), 7.10 (t, J=1.6 Hz, 1H), 7.13 (t, J=1.6 Hz, 1H), 7.17 (s,8H), 7.42 (d, J=1.6 Hz, 2H), 7.54 (d, J=1.6 Hz, 2H), 7.83-7.88 (br, 1H),7.97-8.00 (br, 1H); ¹³C NMR (100 MHz, CDCl₃): δ=23.2, 31.5, 31.5, 33.3,34.9, 34.9, 63.5, 68.9, 70.5, 73.4, 112.1, 113.5, 116.0, 116.6, 129.0,136.9, 138.5, 138.7, 150.8, 151.0, 153.3, 171.3; HRMS (ESI): m/z [M+H]⁺:C₅₇H₈₃N₂O₉ calcd. 939.6099. found 939.6062.

Example 10 Amide 3

In this example, amide 3 having its carbonyl moiety conjugated to anaromatic ring was used as the guest molecule. NaTFPB was used as thetemplating salt. MC1 was used as the host molecule. SA1 or SA5 was usedas the stoppering agent. DBTDL was used as a catalyst for capping theSA1 to the amide 3. For preparing the rotaxane 12 or 13, a CH₂Cl₂solution containing amide 3, NaTFPB, MC1 and DBTDL was added SA1 or SA5,and stirred at ambient temperature for 16 hours.

The amide groups in amides 2 and 3 have their N—H and carbonyl motif toattached directly to the aromatic ring, respectively. The higher yieldin the synthesis of rotaxane 11 compared to the one of rotaxane 12 islikely to because of the aromatic conjugation, which makes the NH protonin amide 2 more acidic than the one in amide 3 and thus, enhanced itscomplexation to MC1.

The successful synthesis of rotaxane 13 by using SA5 as the stopperingreagent, eliminates the possibility that threading the carbonyl group ofSA1 into the cavity of the macrocycle in the presence of a templatingNa⁺ ion is the key intermediate in the syntheses of rotaxanes 1-12 andconfirms the formation of the pseudorotaxane structure based on therecognition of MC1 and the guest units through a templating Na⁺ ion insolution. The relative low yield (10%) in the synthesis of rotaxane 13compared to the one of rotaxane 12, can be rationalized by the releaseof triflate anions during the reaction progress, which destabilized thecorresponding pseudorotaxanes by weakening the metal ion chelatingand/or hydrogen bonding interactions among the components.

All related spectral data of rotaxane 12 and 13 are listed below. The ¹HNMR and ¹³C NMR spectra of rotaxane 12 are shown in FIGS. 10A and 10B,respectively.

Rotaxane 12: ¹H NMR (400 MHz, CDCl₃): δ=0.80-0.90 (m, 2H), 1.36 (s,18H), 1.40 (18H), 2.25-2.31 (m, 2H), 3.26 (t, J=6 Hz, 2H), 3.50-3.70 (m,16H), 4.26 (d, J=10.8 Hz, 4H), 4.34 (d, J=10.8 Hz, 4H), 6.55-6.60 (br,1H), 7.08 (t, J=1.6 Hz, 1H), 7.14 (s, 8H), 7.43 (d, J=1.6 Hz, 2H), 7.54(t, J=1.6 Hz, 1H), 7.63 (d, J=1.6 Hz, 2H), 7.97-8.00 (br, 1H); ¹³C NMR(100 MHz, CDCl₃): δ=27.2, 31.6, 35.0, 35.0, 36.9, 62.2, 68.8, 70.4,73.3, 112.5, 116.0, 121.3, 124.5, 128.9, 135.7, 136.9, 138.6, 150.4,151.0, 153.4, 168.0 (one signal is missing, possibly because of signaloverlapping); HRMS (ESI): m/z [M+H]⁺: C₅₇H₈₃N₂O₉ calcd. 939.6099. found939.6126; [M+Na]⁺: C₅₇H₈₂N₂O₉Na calcd. 961.5918. found 961.5944.

Rotaxane 13: ¹H NMR (400 MHz, CDCl₃): 8=0.65-0.75 (m, 2H), 1.04-1.15 (m,23H), 1.39 (18H), 3.09 (t, J=6.4 Hz, 2H), 3.50-3.70 (m, 16H), 4.24 (d,J=10.8 Hz, 4H), 4.34 (d, J=10.8 Hz, 4H), 7.02-7.10 (m, 9H), 7.55 (d,J=1.6 Hz, 2H), 7.90 (s, 1H); ¹³C NMR (100 MHz, CDCl₃): 8=12.1, 18.3,26.6, 31.8, 32.8, 35.1, 63.5, 68.8, 70.6, 73.2, 113.9, 115.7, 128.6,136.9, 139.4, 150.4, 170.2; HRMS (ESI): m/z [M+Na]⁺: C₅₁H₈₁NO₈SiNacalcd. 886.5629. found 886.5657.

Example 11 Amide 4 Containing One Glycine Residue

In this example, amide 4 containing one C-amidated glycine moiety andhaving an amide group conjugated to no aromatic rings was used as theguest molecule. NaTFPB or NaClO₄ was used as the templating salt. MC1,MC5, or MC6 was used as the host molecule. SA1 or SA6 was used as thestoppering agent. For preparing the rotaxanes 14-17, a CH₂Cl₂ solutioncontaining amide 4, the macrocyclic host and the templating salt wasadded the stoppering agent and stirred at ambient temperature for 16hours.

From the result above, it can be seen that even though the amide moietyis not directly linking to any aromatic rings, threading of a singleamide unit through the cavity of a macrocytic molecule in the presenceof a templating Na⁺ ion is still feasible. Using SA6 as the stopperingreagent, rotaxane 16 and 17 can still be synthesized in reasonableyields. This result suggested that no additional functionality will needto be introduced into the main chain structure of the peptide (unlikethe urea moiety found in rotaxane 14), thereby allowing this recognitionsystem to be used for constructing interlocked or interwoven structuresfeaturing pure peptide chains. The successful syntheses of rotaxanes14-17 also suggested that counter anion for the Na⁺ ion template is notonly limited to TFPB, other weakly ion-pairing anions, such as ClO₄ ⁻can also be used. Moreover, the above results suggested that therecognition of the host molecules above required only one single amidefunctionality, thereby potentially allowing higher-order [n]rotaxanes tobe prepared from relatively long peptides.

When LiTFPB and KTFPB were used in place of NaTFPB in the synthesis ofrotaxane 15 under similar conditions, the yield of the [2]rotaxanedropped to 9% and 4%, respectively, suggesting that Li⁺ and K⁺ ions arealso qualified templates in such a recognition system but just not asgood as Na⁺ ions.

All related spectral data of rotaxane 14-17 are listed below. The ¹H NMRand ¹³C NMR spectra of rotaxane 14 and 17 are shown in FIGS. 11 and 12,respectively.

The solid state structure of rotaxane 16 is shown in FIG. 13. Singlecrystals suitable for X-ray crystallography were grew through liquiddiffusion of hexane into a CH₂Cl₂ solution of rotaxane 16. The solidstate structure of rotaxane 16 reveals the expected geometry, in whichthe amide group of the threadlike component penetrated MC1 and had itsNH proton hydrogen bonding to the oxygen atoms of the ethylene glycolchain of MC1.

Rotaxane 14: M.p. 152-153° C.; ¹H NMR (400 MHz, CDCl₃): δ=1.36 (s. 18H),1.36 (s, 18H), 2.35 (d, J=3.6 Hz, 2H), 3.48-3.62 (m, 16H), 4.21 (d,J=5.6 Hz, 2H), 4.28 (d, J=10.8 Hz, 4H), 4.29 (d, J=10.8 Hz, 4H),4.80-4.83 (t, J=3.6 Hz, 1H), 6.60-6.65 (br, 1H), 7.00 (t, J=1.6 Hz, 1H),7.10 (s, 8H), 7.19 (d, J=2 Hz, 2H), 7.35 (t, J=1.6 Hz, 1H), 7.40 (d, J=2Hz, 2H), 7.55 (s, 1H); ¹³C NMR (100 MHz, CDCl₃): 6=31.6, 31.7, 34.9,35.0, 41.7, 44.2, 68.8, 70.4, 73.3, 112.4, 114.8, 121.4, 123.5, 128.5,136.6, 137.6, 140.3, 150.6, 150.7, 153.9, 168.1; HRMS (ESI): m/z [M+H]⁺:C₅₆H₈₂N₃O₈ calcd. 924.6102. found 924.6133; [M+Na]⁺: C₅₆H₈₁N₃O₈Na calcd.946.5921. found 946.5948.

Rotaxane 15: ¹H NMR (400 MHz, CDCl₃): δ=1.26 (s, 18H), 1.28 (s, 18H),2.45 (d, J=2.4 Hz, 2H), 3.49-3.68 (m, 8H), 4.19 (d, J=4.8 Hz, 2H), 4.25(d, J=10.8 Hz, 2H), 4.29 (d, J=10.8 Hz, 2H), 4.36 (s, 4H), 4.44 (d,J=11.6 Hz, 2H), 4.50 (d, J=11.6 Hz, 2H), 5.30 (s, 1H), 6.96 (s, 1H),7.12 (s, 10H), 7.22-7.32 (m, 4H), 7.50 (s, 1H), 7.67 (t, J=8 Hz, 1H),8.09 (s, 1H); ¹³C NMR (100 MHz, CDCl₃): 6=31.4, 31.5, 34.7, 34.8, 41.6,44.1, 69.1, 70.6, 71.1, 72.6, 73.3, 112.3, 114.7, 120.4, 121.4, 123.6,128.5, 128.6, 136.3, 136.9, 137.4, 137.5, 140.5, 150.7, 150.8, 154.3,157.4, 167.8; HRMS (ESI): m/z [M+H]⁺: C₅₉H₈₁N₄O₇ cal. for 957.6105.found 957.6077; [M+Na]⁺: C₅₉H₈₀N₄O₇Na cal. for 979.5925. found 979.5911.

Rotaxane 16: M.p. 150-151° C.; ¹H NMR (400 MHz, CDCl₃): δ=1.34 (s, 18H),1.39 (s, 18H), 3.04 (d, J=5.2 Hz, 2H), 3.38-3.50 (m, 16H), 3.79 (d,J=5.2 Hz, 2H), 4.27 (d, J=10.8 Hz, 4H), 4.31 (d, J=10.8 Hz, 4H),6.68-6.71 (br, 1H), 6.90-6.96 (br, 1H), 7.08 (d, J=1.6 Hz, 2H), 7.11 (s,8H), 7.30 (t, J=1.6 Hz, 1H), 7.51 (t, J=1.6 Hz, 1H), 7.57 (d, J=1.6 Hz,2H); ¹³C NMR (100 MHz, CDCl₃): 6=31.5, 31.6, 34.8, 35.0, 42.8, 43.7,68.8, 70.3, 73.2, 121.0, 121.8, 123.4, 124.6, 128.7, 134.8, 136.8,137.7, 150.1, 150.2, 167.5 (one signal is missing, possibly because ofsignal overlapping); HRMS (ESI): m/z [M+H]⁺: C₅₆H₈₁N₂O₈ calcd. 909.5993.found 909.6069; [M+Na]⁺: C₅₆H₈₀N₂O₈Na calcd. 931.5812. found 931.5808.

Rotaxane 17: ¹H NMR (400 MHz, CD₃COCD₃): δ=1.24 (s, 18H), 1.33 (s, 18H),3.35-3.42 (m, 2H), 3.43-3.73 (m, 16H), 4.07 (d, J=12.4 Hz, 2H), 4.13 (d,J=5.6 Hz, 2H), 4.27-4.35 (m, 4H), 4.40 (d, J=11.2 Hz, 2H), 6.93 (d,J=7.6 Hz, 2H), 7.00 (s, 4H), 7.08 (d, J=1.6 Hz, 2H), 7.30-7.36 (m, 2H),7.47 (s, 3H), 7.58 (t, J=5.6 Hz, 1H), 8.40 (d, J=5.8 Hz, 1H); ¹³C NMR(100 MHz, CD₃COCD₃): δ=31.8, 31.9, 35.2, 35.4, 43.9, 44.4, 69.3, 70.5,71.0, 71.0, 73.5, 73.7, 120.8, 121.6, 123.1, 124.1, 124.9, 129.2, 134.8,137.2, 138.1, 140.2, 150.0, 151.0, 158.1, 166.9, 170.1; HRMS (ESI): m/z[M+H]⁺: C₅₅H₈₀N₃O₈ calcd. 910.5945. found 910.5978; [M+Na]⁺ C₅₅H₇₉NaN₃O₈calcd. 932.5764. found 932.5791.

Example 12 Amide 5 Containing Three Glycine Residues

In this example, amide 5 containing three glycine residues was used asthe guest molecule. The template ion, the host molecule, and thestoppering agent were NaClO₄, MC1, and SA6, respectively. For preparingthe [2]rotaxane 18 and the [3]rotaxane 19, a CH₂Cl₂ solution containingamide 5, NaClO₄, and MC1 was added with SA6, and stirred at ambienttemperature for 16 hours.

Amide 6 has three amide units presented in its gly-gly-gly backbone forthe binding of MC1. The isolation of [3]rotaxane 19 suggested that thethree amide units in amide 5 can, at least, accommodate two MC1 hosts inthe same time. This result demonstrates the potential application ofthis recognition system in the assembly of interlocked structures frompeptides and other amide bond containing bio- or artificial(macro)molecules.

The ¹H NMR and ¹³C NMR spectra of rotaxane 18 and 19 are shown in FIGS.14 and 15, respectively. All related spectral data are listed below.

[2]Rotaxane 18: ¹H NMR (400 MHz, CD₃COCD₃): δ=1.34 (s, 18H), 1.38 (s,18H), 3.15 (d, J=5.6 Hz, 2H), 3.29 (d, J=4.8 Hz, 2H), 3.49-3.61 (m,16H), 3.94 (d, J=5.6 Hz, 2H), 4.30 (d, J=5.6 Hz, 2H), 4.34 (s, 8H), 6.60(t, J=5.2 Hz, 1H), 6.91 (t, J=4.8 Hz, 1H), 7.04 (t, J=5.2 Hz, 1H), 7.10(s, 8H), 7.24 (d, J=2 Hz, 2H), 7.40 (t, J=2 Hz, 1H), 7.67 (t, J=2 Hz,1H), 7.86 (d, J=2 Hz, 2H), 7.99 (t, J=5.6 Hz, 1H); ¹³C NMR (100 MHz,CD₃COCD₃): δ=31.8, 31.9, 35.4, 35.6, 42.8, 43.0, 43.8, 44.1, 69.7, 71.0,73.6, 121.8, 122.4, 123.2, 125.9, 129.3, 135.0, 137.9, 139.2, 151.2,151.3, 168.0, 168.3, 168.7, 169.3; HRMS (ESI): m/z [M+H]⁺: C₆₀H₈₇N₄O₁₀calcd. 1023.6422. found 1023.6401; [M+Na]⁺: C₆₀H₈₆N₄O₁₀Na calcd.1045.6242. found 1045.6211.

[3]Rotaxane 19: ¹H NMR (400 MHz, CD₃COCD₃): δ=1.38 (s, 18H), 1.44 (s,18H), 2.75 (d, J=4.8 Hz, 2H), 3.02 (d, J=5.2 Hz, 2H), 3.36-3.71 (m,34H), 3.89 (d, J=5.6 Hz, 2H), 4.35-4.40 (m, 8H), 4.49-4.56 (m, 8H), 6.38(t, J=4.8 Hz, 1H), 6.60 (t, J=5.2 Hz, 1H), 6.94 (t, J=5.6 Hz, 1H), 7.12(d, J=2 Hz, 2H), 7.24 (s, 9H), 7.30 (s, 8H), 7.40 (t, J=2 Hz, 1H), 7.66(s, 3H); ¹³C NMR (100 MHz, CD₃COCD₃): δ=31.9, 32.0, 35.5, 35.7, 42.7,43.0, 43.2, 44.3, 69.6, 69.7, 71.1, 71.2, 73.5, 73.6, 121.6, 122.8,123.8, 125.4, 129.4, 129.5, 136.2, 138.1, 138.1, 139.3, 150.9, 150.9,167.4, 168.2, 168.7, 168.9; HRMS (ESI): m/z [M+H]⁺: C₈₄H₁₁₉N₄O₁₆ calcd.1439.8621. found 1439.8571; [M+Na]*: C₈₄H₁₁₈N₄O₁₆Na calcd. 1461.8441.found 1461.8384.

Example 13 Amide 6 Containing One Repeating Unit of Nylon-6.6

In this example, amide 6 containing one repeating unit of nylon-6,6 wasused as the guest molecule. The templating salt, the host molecule, andthe stoppering agent were NaClO₄, MC1, and SA6, respectively. Forpreparing the rotaxane 20, a CH₂Cl₂ solution containing amide 6, NaClO₄,and MC1 was added with SA6, and then stirred at ambient temperature for16 hours.

Since amide 6 containing the repeating unit of nylon-6,6, the successfulsynthesis of rotaxane 20 supported that such a Na⁺ ion-assistedhost-guest complexation system can be used directly to form interwovenor interlocked structures from common peptides and other amide bondcontaining bio- and artificial (macro)molecules without alternatingtheir key molecular structures.

The ¹H NMR and ¹³C NMR spectra of rotaxane 20 are shown in FIGS. 16A and16B, respectively. All related spectral data are listed below.

rotaxane 20: M.p. 161-163° C.; ¹H NMR (400 MHz, CD₃COCD₃): δ=0.82-1.02(m, 8H), 1.14-1.25 (m, 4H), 1.32 (s, 18H), 1.37 (s, 18H), 1.91 (t, J=6.8Hz, 2H), 1.97 (t, J=7.2 Hz, 2H), 2.67 (q, J=6.4 Hz, 2H), 2.99 (q, J=6.8Hz, 2H), 3.48-3.54 (m, 16H), 4.31 (d, J=5.6 Hz, 2H), 4.34 (s, 8H),6.40-6.45 (br, 1H), 7.16-7.23 (m, 11H), 7.36 (t, J=1.6 Hz, 1H),7.42-7.47 (br, 1H), 7.62 (t, J=1.6 Hz, 1H), 7.79 (d, J=1.6 Hz, 2H); ¹³CNMR (100 MHz, CD₃COCD₃): 6=25.8, 26.0, 27.1, 27.3, 31.8, 31.9, 35.3,35.6, 36.6, 36.6, 39.5, 40.3, 44.0, 69.3, 71.0, 73.5, 121.4, 122.1,122.7, 125.3, 129.4, 136.0, 138.1, 139.7, 151.0, 151.1, 167.5, 172.1,172.6 (two signals are missing, possibly because of signal overlapping);HRMS (ESI): m/z [M+Na]⁺: C₆₆H₉₉N₃O₉Na calcd. 1100.7279. found 1100.7243.

Embodiment 4 Guest Molecules Containing at Least One Oligo(EthyleneGlycol)Group Example 14 Ether 1 Containing a Di-ethylene Glycol Moiety

In this example, ether 1 containing a diethylene glycol segment was usedis as the guest molecule. NaTFPB was used as the templating salt. MC1was used as the host molecule. SA7 was used as the stoppering agent. Forpreparing the rotaxane 21, a solid mixture obtained from concentrating aCH₂Cl₂ solution mixture of ether 1, NaTFPB and MC1 was mixed with solidSA7 and ball-milled at 20 Hz for 90 minutes.

Since ether 1 and MC1 contain only aromatic and diethylene glycol units,between which hydrogen bond cannot be generated, the pseudorotaxaneprecursor for the synthesis of rotaxane 21 must be assembled by usingNa⁺ ion to template the threading the diethylene glycol segment of ether1 into MC1.

The ¹H NMR and ¹³C NMR spectra of rotaxane 21 are shown in FIGS. 17A and17B, respectively. All related spectral data are listed below.

rotaxane 21: ¹H NMR (400 MHz, CDCl₃): δ=1.33 (s, 18H), 2.63-2.74 (m,2H), 2.75-2.83 (m, 2H), 2.91-3.01 (m, 1H), 3.01-3.09 (m, 1H), 3.09-3.31(m, 6H), 3.33-3.55 (m, 21H), 3.63-3.74 (m, 1H), 3.86-3.97 (m, 1H),4.03-4.14 (m, 1H), 4.29-4.39 (m, 8H), 4.43 (s, 2H), 7.09 (s, 8H),7.16-7.22 (m, 6H), 7.30-7.41 (m, 4H), 7.49-7.55 (m, 1H); ¹³C NMR (100MHz, CDCl₃): δ=31.6, 33.2, 34.9, 36.7, 47.5, 68.0, 68.5, 68.9, 69.1,69.4, 69.5, 70.3, 73.1, 73.9, 121.5, 122.0, 125.9, 126.5, 126.6, 127.4,127.8, 128.7, 129.5, 129.9, 130.0, 130.7, 131.6, 133.9, 137.2, 137.3,137.5, 141.5, 146.0, 150.4; HRMS (ESI): m/z [M+H]⁺ C₆₁H₈₀N₃O₉ calcd.998.5894. found 998.5837; [M+Na]⁺: C₆₁H₈₆₇₉N₃O₉Na calcd. 1020.5714.found 1020.5688.

Example 15 Ether 2 Containing a Tri-ethylene Glycol Moiety

In this example, ether 2 containing a triethylene glycol segment wasused as the guest molecule. NaTFPB was used as the templating salt. MC1was used as the host molecule. SA7 was used as the stoppering agent. Forpreparing the rotaxane 22, a solid mixture obtained from concentrating aCH₂Cl₂ solution mixture of ether 2, NaTFPB and MC1 was mixed with solidSA7 and ball-milled at 20 Hz for 90 minutes.

The higher yield in the synthesis of rotaxane 22 compared to the one ofrotaxane 21 under similar condition is likely to due to the triethyleneglycol motif of ether 2 contains more oxygen atoms than the diethyleneglycol one of ether 1, to which increases its affinity to the templatingNa⁺ ion and stabilizes the corresponding pseudorotaxane more.

All related spectral data of rotaxane 22 are listed below.

rotaxane 22: ¹H NMR (400 MHz, CDCl₃): δ=1.31 (s, 18H), 2.73-2.82 (m,2H), 2.82-2.89 (m, 2H), 2.89-2.99 (m, 2H), 3.07-3.21 (m, 6H), 3.24-3.30(m, 2H), 3.36-3.51 (m, 20H), 3.91-4.03 (m, 1H), 4.08-4.19 (m, 1H),4.27-4.40 (m, 8H), 4.45 (s, 2H), 4.457.11 (s, 8H), 7.14-7.23 (m, 6H),7.28-7.41 (m, 4H), 7.49-7.53 (m, 1H); ¹³C NMR (100 MHz, CDCl₃): δ=31.6,33.2, 34.9, 36.7, 47.5, 68.2, 68.5, 69.2, 69.2, 69.3, 69.7, 70.1, 70.3,73.1, 73.9, 121.5, 122.0, 125.9, 126.5, 126.5, 127.8, 128.7, 129.4,129.9, 129.9, 130.7, 131.6, 133.9, 137.2, 137.2, 137.3, 137.5, 141.5,146.0, 150.5 (one signals is missing, possibly because of signaloverlapping); HRMS (ESI): m/z [M+H]⁺ C₆₃H₈₄N₃O₁₀ calcd. 1042.6156. found1042.6188.

Example 16 Ether 3 Containing a Tetra-ethylene Glycol Moiety

In this example, ether 3 containing a tetra-ethylene glycol segment wasused as the guest molecule. NaTFPB was used as the templating salt. MC1was used as the host molecule. SA3 was used as the stoppering agent. Forpreparing the rotaxane 23, a sticky liquid obtained from concentrating aCH₂Cl₂ solution mixture of ether 3, NaTFPB and MC1 was mixed with SA3and the neat mixture was stirred until solidified.

Compared to ether 2, ether 3 contains an even longer ethylene glycolchain for binding the Na⁺ ion template. The relatively low yield in thesynthesis of rotaxane 23 compared to the one of rotaxane 22, however,may due to different stoppering method applied or the increasingtendency for ether 3 to bind Na⁺ ion template alone.

The ¹H NMR and ¹³C NMR spectra of rotaxane 23 are shown in FIGS. 18A and18B, respectively. All related spectral data are listed below.

rotaxane 23: ¹H NMR (400 MHz, CDCl₃, 298 K): δ=1.30 (s, 18H), 1.32 (s,18H), 3.39-3.69 (m, 32H), 3.80 (d, J=5.3 Hz, 2H), 4.21-4.34 (m, 10H),4.50 (s, 2H), 4.52 (s, 2H), 5.81 (t, J=4.7 Hz, 1H), 6.95 (s, 8H),7.03-7.08 (m, 4H), 7.14 . . . 7.20 (m, 4H), 7.30 (d, J=10.2 Hz, 2H); ¹³CNMR (100 MHz, CDCl₃, 298 K): δ=31.6, 31.7, 34.9, 34.9, 45.6, 65.1, 68.6,69.2, 69.4, 70.3, 70.6, 73.1, 73.9, (five aliphatic carbon signals aremissing possibly because of signal overlapping) 120.9, 121.5, 121.9,123.0, 126.8, 127.5, 128.4, 136.3, 136.8, 137.1, 137.5, 150.3, 150.5,155.6; (one aromatic carbon signal is missing possibly because of signaloverlap); HRMS (ESI): m/z [M+H]⁺ C₇₁H₁₀₄NO₁₃ calcd. 1178.7507. found1178.7553.

Embodiment 5 Using Diamine and dialdehyde to Synthesize Host Molecules,Guest Molecules, or Both Example 17 DAM1 Containing a Di-ethylene GlycolMoiety

In this example, DAM1 containing a diethylene glycol segment was used asthe guest molecule. NaTFPB was used as the templating salt. MC7, whichin situ generated from the imine formation reaction of DAM1 and DAD1 wasused as the host molecule. For preparing the catenane 1, DAM1, NaTFPBand DAD1 were mixed in CH₂Cl₂ and the solution mixture was stirred at50° C. for 16 hours.

Spectra 19A-19C in FIG. 19 are the partial ¹H NMR spectra (400 MHz,CDCl₃, 298 K) displaying the formation of catenane 1 from an mixture ofDAM1, DAD1, and NaTFPB (20 mM: 20 mM: 10 mM) over time. A new set ofsignals corresponding to catenane 1 was observed in the original mixture(spectrum 19B), which then became the predominated species in solutionafter 3 hours (spectrum 19C). Comparing spectra 19A and 19C, thedisappearance of the aldehyde signal at δ 10.10 and the appearance ofthe imine signal at δ8.42, suggested that the DAD1 and DAM1 have beenlinked by imine bonds. The significant upfield shifted of the diethyleneglycol signal at δ 2.59 and 2.98 in the ¹H NMR spectrum, indicated itslocation in the shielding zone of the xylene groups and supported theformation of the catenane 1.

According to similar NMR experiments, signals belong to catenane 1cannot be observed in the spectra when zero or one equivalent of NaTFPBwas applied under similar reaction condition. This result not onlysuggested that Na⁺ ion is a crucial template for the formation ofcatenane 1 but also supported the need for two diethylene glycol chainsin such a complexation.

Since imine bonds are easily hydrolyzed, catenane 1 was not subject tofurther purification. PhSeH was used to reduce the imine bonds incatenane 1 and catenane 2, which has two MC8 interlocked, was isolatedin 17% yield after column chromatography. According to the ¹H NMRspectrum, catenane 1 was the predominate species in solution; therelative low yield in the synthesis of catenane 2, however, suggestedthat the PhSeH reduction reaction is not efficient enough to prevent thedissociation of the components.

MC7 contains a diethylene glycol, a 1,3-bis(iminomethyl)benzene and twoxylene groups. The formation of catenane 1 in solution suggested thatDAM1 is capable to thread through MC7 with the assistance from Na⁺ iontemplate. This result confirmed that pseudorotaxane formed fromthreading to one oligo(ethylene glycol) containing guest into anotheroligo(ethylene glycol) containing macrocycle can not only be used tosynthesize rotaxanes but also to construct catenanes. Therefore,pseudorotaxanes formed from guests containing urea, carbamate and amidegroups and similar macrocyclic imine hosts should also be reasonableprecursors for preparing the corresponding catenanes and rotaxanes.

All related spectral data of catenane 2 are listed below. The ¹H NMR and¹³C NMR spectra of catenane 2 are shown in FIGS. 20A and 20B,respectively.

Catenane 2: ¹H NMR (400 MHz, CDCl₃): 6=3.20-3.35 (br, 16H), 3.37-3.43(br, 8H), 3.45-3.51 (br, 8H), 4.32 (s, 8H), 6.90-7.03 (br, 18H),7.06-7.11 (br, 4H), 7.24 (t, J=8 Hz, 4H); ¹³C NMR (100 MHz, CD₃OD):δ=¹³C NMR (100 MHz, CD₃OD): δ5=53.9, 54.6, 70.1, 71.2, 74.1, 128.2,129.1, 129.7, 130.0, 130.1, 138.1, 140.2, 140.8; HR-MS (ESI): m/z calcdfor [M+H]C₅₆H₆₉N₄O₆ ⁺: 893.5212. found 893.5158.

Example 18 MC1 Containing Two Di-ethylene Glycol Moiety

In this example, DAM2 containing a 2,6-bis(hydroxymethyl)pyridinesegment was used as the guest molecule. NaTFPB was used as thetemplating salt. MC1 was used as the host molecule. For preparing thecatenane 3, DAM2, NaTFPB and DAD1 were mixed in CH₂Cl₂ and the solutionmixture was stirred at 50° C. for 48 hours.

Since imine bonds are easily hydrolyzed, catenane 3, which has MC1 andMC9 interlocked, was not subject to further purification. PhSeH was usedto reduce the imine bonds in catenane 3 and catenane 4, which has MC1and MC10 interlocked, was isolated in 7% yield after columnchromatography.

MC1 contains two diethylene glycol and two xylene groups. MC9 contains a2,6-bis(hydroxymethyl)pyridine, a 1,3-bis(iminomethyl)benzene and twoxylene groups. The formation of catenane 3 in solution suggested thatthe 2,6-bis(hydroxymethyl)pyridine motif in DAM2 is also capable tothread through MC1 with the assistance from Na⁺ ion template. In theother hand, this result also suggested that the2,6-bis(hydroxymethyl)pyridine motif in MC9 is also capable toaccommodate the threading of an oligo(ethylene) glycol-containing guestunder similar condition.

All related spectral data of catenane 4 are listed below. The ¹H NMR and¹³C NMR spectra of catenane 4 are shown in FIGS. 21A and 21B,respectively.

Catenane 4: ¹H NMR (400 MHz, CD₃CN): δ=3.05 (t, J=6 Hz, 8H), 3.16-3.21(m, 12H), 3.30 (s, 4H), 4.14 (s, 8H), 4.30 (s, 4H), 4.59 (s, 4H),6.93-6.98 (m, 10H), 7.02 (s, 1H), 7.10 (d, J=8 Hz, 4H), 7.15 (t, J=8 Hz,1H), 7.19 (d, J=8 Hz, 4H), 7.33 (d, J=8 Hz, 2H), 7.72 (t, J=8 Hz, 1H);¹³C NMR (100 MHz, CD₃CN): δ=54.3, 54.7, 69.0, 70.5, 71.5, 72.8, 73.3,120.3, 26.8, 127.4, 128.7, 128.8, 129.4, 129.7, 136.6, 137.8, 138.1,41.2, 141.5, 158.4; HR-MS (ESI): m/z calcd for [M+H]⁺ C₅₅H₆₆N₃O₈ ⁺:896.4850. found 896.4850.

Example 19 DAM2 Containing a 2,6-Bis(hydroxymethyl)pyridine Moiety andDAD1

In this example, DAM2 containing a 2,6-bis(hydroxymethyl)pyridinesegment was used as the guest molecule. NaTFPB was used as thetemplating salt. MC9, which in situ generated from the imine formationreaction of DAM2 and DAD1 was used as the host molecule. For preparingthe catenane 5, DAM2, NaTFPB and DAD1 were mixed in CH₂Cl₂ and thesolution mixture was stirred at 50° C. for 48 hours.

Since imine bonds are easily hydrolyzed, catenane 5 was not subject tofurther purification. PhSeH was used to reduce the imine bonds incatenane 5 and catenane 6, which has two MC10 interlocked, was isolatedin 34% yield after column chromatography.

MC9 contains a 2,6-bis(hydroxymethyl)pyridine, a1,3-bis(iminomethyl)benzene and two xylene groups. The formation ofcatenane 5 in solution suggested that DAM2 is capable to thread throughMC9 with the assistance from Na⁺ ion template. This result confirmedthat pseudorotaxane formed by threading one2,6-bis(hydroxymethyl)pyridine containing guest into another2,6-bis(hydroxymethyl)pyridine containing macrocycle can not only beused to synthesize rotaxanes but also to construct catenanes. Therefore,pseudorotaxane formed from guests containing urea, carbamate, amide oroligo(ethylene glycol) group and similar macrocyclic imine hosts shouldalso be reasonable precursors for preparing the corresponding catenanesand rotaxanes.

All related spectral data of catenane 6 are listed below. The ¹H NMR and¹³C NMR spectra of catenane 6 are shown in FIGS. 22A and 22B,respectively.

Catenane 6: ¹H NMR (400 MHz, CD₃CN): 6=3.03 (s, 8H), 3.08 (s, 8H), 4.35(s, 8H), 4.54 (s, 8H), 6.83-6.90 (m, 16H), 7.06 (d, J=8 Hz, 8H), 7.14(t, J 15=8 Hz, 2H), 7.35 (d, J=8 Hz, 4H), 7.75 (t, J=8 Hz, 2H); ¹³C NMR(100 MHz, CD₃CN): δ=54.6, 71.7, 73.0, 120.3, 127.6, 128.4, 129.5, 129.7,129.8, 137.2, 138.2, 141.3, 141.4, 158.9 (one signal is missing,possibly because of signal overlapping); HR-MS (ESI): m/z calcd for[M+H]⁺ C₆₂H₆₇N₆O₄ ⁺: 959.5218. found 959.5269.

Example 20 DAM2 Containing 2,6-Bis(hydroxymethyl)pyridine Moiety andDAD2

In this example, DAM2 containing a 2,6-bis(hydroxymethyl)pyridinesegment was used as the guest molecule. NaTFPB was used as thetemplating salt. MC1 was used as the host molecule. For preparing thecatenane 7, DAM2, NaTFPB and DAD2 were mixed in CH₂Cl₂ and the solutionmixture was stirred at 50° C. for 48 hours.

Since imine bonds are easily hydrolyzed, catenane 7 was not subject tofurther purification. PhSeH was used to reduce the imine bonds incatenane 7 and catenane 8, which has MC1 and MC12 interlocked, wasisolated in 4% yield after column chromatography.

MC1 contains two diethylene glycol and two xylene groups. MC11 containsa 2,6-bis(hydroxymethyl)pyridine, a 2,6-bis(iminomethyl)pyridine and twoxylene groups. The formation of catenane 7 in solution indicated thatDAD2 is also capable to cyclize the pseudorotaxane formed from DAM2, MC1and Na⁺ ion and suggested the existence of structural flexibilities inthe dialdehyde used in such a self-assembly approach.

All related spectral data of catenane 8 are listed below. The ¹H NMR and¹³C NMR spectra of catenane 8 are shown in FIGS. 23A and 23B,respectively.

Catenane 8: ¹H NMR (400 MHz, CD₃CN): δ=3.10-3.15 (br, 8H), 3.18-3.23(br, 8H), 3.30 (br, 4H), 3.34 (s, 4H), 4.11 (s, 8H), 4.32 (s, 4H), 4.57(s, 4H), 6.97 (s, 8H), 7.03-7.10 (m, 6H), 7.18 (d, J=8 Hz, 4H), 7.33 (d,J=8 Hz, 2H), 7.63 (t, J=8 Hz, 1H), 7.73 ppm (t, J=8 Hz, 1H); ¹³C NMR(100 MHz, CD₃CN): δ=54.5, 55.5, 69.4, 70.7, 71.8, 73.0, 73.4, 120.6,121.3, 129.4, 129.6, 130.1, 137.3, 138.1, 138.6, 158.9 ppm (threesignals are missing, possibly because of signals overlapping); HR-MS(ESI): m/z calcd for [M+H]⁺ C₅₄H₆₅N₄O₈ ⁺: 897.4797. found 897.4785.

Example 21 Urea 6 Containing a Urea Moiety

In this example, urea 6 was used as the dumbbell-shaped guest. DAM2 andDAD2 were used to generate MC11 in situ. NaTFPB was used as thetemplating salt. For preparing rotaxane 24, urea 6, DAM2, NaTFPB andDAD2 were mixed in CH₂Cl₂ and the solution mixture was stirred at 50° C.for 16 hours.

Since imine bonds are easily hydrolyzed, rotaxane 24 was not subject tofurther purification. PhSeH was used to reduce the imine bonds inrotaxane 24 and rotaxane 25, which has MC12 interlocked inside urea 6,was isolated in 3% yield after column chromatography.

MC11 contains a 2,6-bis(hydroxymethyl)pyridine, a2,6-bis(iminomethyl)pyridine and two xylene groups. The formation ofrotaxane 24 in solution indicated that Na⁺ ion is capable to templatethe formation and encircling of MC11 on the urea functionality of urea6. Thus, the same imine-formation “clipping” approach should also allowthe formation of rotaxanes or catenanes from similar macrocyclic iminehost and guests containing urea, carbamate, amide, oligo(ethyleneglycol) and 2,6-bis(hydroxymethyl)pyridine groups.

All related spectral data of rotaxane 25 are listed below. The ¹H NMRand ¹³C NMR spectra of rotaxane 25 are shown in FIGS. 24A and 24B,respectively.

Rotaxane 25: ¹H NMR (400 MHz, CDCl₃): δ=1.23 (s, 36H), 3.68 (s, 4H),3.91 (s, 4H), 4.46 (s, 4H), 4.48 (s, 4H), 6.76-6.81 (m, 8H), 6.87 (d,J=8 Hz, 4H), 6.90 (t, J=2 Hz, 2H), 7.14 (d, J=8 Hz, 2H), 7.41 (d, J=8Hz, 2H), 7.58 (t, J=8 Hz, 1H), 7.80 (t, J=8 Hz, 1H); ¹³C NMR (400 MHz,CDCl₃): 6=31.5, 34.7, 54.4, 56.4, 70.8, 73.4, 112.6, 114.7, 120.8,121.2, 127.5, 128.6, 133.6, 136.3, 138.0, 139.5, 140.7, 150.3, 150.7,157.9, 159.4; HR-MS (ESI): m/z calcd for [M+H]⁺ C₅₉H₇₇N₆O₃ ⁺: 917.6057.found 917.6057.

Accordingly, a new molecular recognition system has been discovered. Inthis new recognition system, a single recognition moiety, such as a ureagroup, a carbamate group, an amide group, an oligo(ethylene glycol)group or a 2,6-bis(hydroxymethyl)pyridine, of a threaded guest moleculecan be recognized by a host molecule having a macrocyclic structurecontaining at least a binding unit (an oligo(ethylene glycol) group or a2,6-bis(hydroxymethyl)pyridine group) and an aromatic linking spacer viaa templating metal ion. This recognition system can also be applied on aguest molecule containing glycine residues, a repeating unit of Kelvaror a repeating unit of nylon-6,6. The extremely high structuralflexibility of the guests for this recognition system will facilitatethe introduction of interlocked or interwoven structures into(bio)materials found commonly in our daily lives to endow them with newfunctions or properties.

All the features disclosed in this specification (including anyaccompanying claims, abstract, and drawings) may be replaced byalternative features serving the same, equivalent or similar purpose,unless expressly stated otherwise. Thus, each feature disclosed is oneexample only of a generic series of equivalent or similar features.

What is claimed is:
 1. A pseudorotaxane complex comprising: a hostmolecule having a macrocycle structure comprising at least a bindingunit and an aromatic linking spacer, wherein the binding unit is2,6-bis(hydroxymethyl)pyridine; a guest molecule having at least arecognition moiety, wherein the recognition moiety is a urea group, acarbamate group, an amide group, an oligo(ethylene glycol) group or a2,6-bis(hydroxymethyl)pyridine group; and a metal ion, wherein the metalion coordinates to the binding unit of the host molecule and therecognition moiety of the guest molecule.
 2. The pseudorotaxane complexof claim 1, wherein the host molecule further comprises a bindingassistant unit, and the binding assistant unit is an oligo(ethyleneglycol) group, a 2,6-bis(hydroxymethyl)pyridine, a2,2′-oxy-di(ethanethiol) group, a 1,3-bis(iminomethyl)benzene group, ora 2,6-bis(iminomethyl)pyridine group.
 3. The pseudorotaxane complex ofclaim 1, wherein the aromatic linking spacer is p-xylenyl group or a2,6-lutidinyl group.
 4. The pseudorotaxane complex of claim 1, whereinthe host molecule is

or


5. The pseudorotaxane complex of claim 1, wherein the guest moleculecontains at least a glycine, a repeating unit of kevlar, or a repeatingunit of nylon-6,6.
 6. The pseudorotaxane complex of claim 1, wherein themetal ion is Li⁺, Na⁺ or K⁺.
 7. A rotaxane or a catenane synthesizedfrom the pseudorotaxane complex of claim 1, comprising: a host moleculehaving a macrocycle structure comprising at least a binding unit and anaromatic linking spacer, wherein the binding unit is2,6-bis(hydroxymethyl)pyridine; and a guest molecule having at least arecognition moiety, wherein the recognition moiety is a urea group, acarbamate group, an amide group, an oligo(ethylene glycol) group, or a2,6-bis(hydroxymethyl)pyridine group.
 8. The rotaxane or catenane ofclaim 7, wherein the host molecule further comprises a binding assistantunit, and the binding assistant unit is an oligo(ethylene glycol) group,a 2,6-bis(hydroxymethyl)pyridine, a 2,2′-oxy-di(ethanethiol) group, a1,3-bis(iminomethyl)benzene group, a 1,3-bis(aminomethyl)benzene group,a 2,6-bis(iminomethyl)pyridine group, or a 2,6-bis(aminomethyl)pyridinegroup.
 9. The rotaxane or catenane of claim 7, wherein the aromaticlinking spacer is a p-xylenyl group or a 2,6-lutidinyl group.
 10. Therotaxane or catenane of claim 7, wherein the host molecule is


11. The rotaxane or catenane of claim 7, wherein the guest moleculecontains at least a glycine, a repeating unit of kevlar, or a repeatingunit of nylon-6,6.